1. Field of the Invention
One disclosed aspect of the embodiments relates to a photoelectric conversion device used in a digital still camera, a video camera, or the like.
2. Description of the Related Art
As demand for higher functionality and higher image quality for photoelectric conversion devices increases, a technique is disclosed in which, by connecting the charge-voltage conversion units in pixels to one another through switches, charges accumulated in photoelectric conversion units can be mixed (for example, see Japanese Patent Laid-Open No. 2009-33316, which is hereinafter referred to as Patent Document 1). In Patent Document 1, a technique is disclosed in which pixel signals which are not mixed are used as image capture signals in a digital still camera or a video camera and in which a mixed pixel signal is used in automatic exposure control.
In Japanese Patent Laid-Open No. 2003-18465 (hereinafter, referred to as Patent Document 2), a configuration is disclosed in which multiple pixel groups provided with switches for addition, each of which is disposed between pixels, are provided, and in which connection switches are used to add signals from the pixel groups.
Regarding the technique described in Patent Document 1, further investigation needs to be carried out from the viewpoint of reading out of signals at a faster speed. In the configuration described in Patent Document 2, the number of pixels whose signals are added in each of the columns is the same. Such a configuration makes it difficult to obtain signals in which a different number of pixels are added depending on a row.